[v7.0] Dropdown: no longer automatically selects the first option when dropdown receives keyboard focus

[TristanWatanabe]

cherry-pick of #17739

Pull request checklist

• Addresses an existing issue: Fixes bug-11604
• Include a change request file using $ yarn change

Description of changes

• removed conditional which selected the first option whenever dropdown receives keyboard focus.
• updated 3 tests to assert that no selection should be made when dropdown receives focus.

New Behavior:

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 3140d91:

Sandbox	Source
Fluent UI Button	Configuration
codesandbox-react-template	Configuration

[size-auditor]

Asset size changes

Project	Bundle	Baseline Size	New Size	Difference
office-ui-fabric-react	office-ui-fabric-react-Dropdown	227.535 kB	227.404 kB	-131 bytes

 Over Tolerance (1024 B)  Over Baseline  Below Baseline  New   Removed 1 kB = 1000 B

Baseline commit: e6387984cb7aeeb11af0d716053d6fcac5eb5ccd (build)

[fabricteam]

Perf Analysis

No significant results to display.

All results

Scenario	Render type	7.0 Ticks	PR Ticks	Iterations	Status
BaseButton	mount	1012	995	5000
Breadcrumb	mount	45571	45875	5000
Checkbox	mount	1735	1715	5000
CheckboxBase	mount	1493	1449	5000
ChoiceGroup	mount	5512	5551	5000
ComboBox	mount	1012	997	1000
CommandBar	mount	8649	8555	1000
ContextualMenu	mount	19223	18939	1000
DefaultButton	mount	1295	1244	5000
DetailsRow	mount	4162	4169	5000
DetailsRowFast	mount	4099	4137	5000
DetailsRowNoStyles	mount	3892	3869	5000
Dialog	mount	1851	1865	1000
DocumentCardTitle	mount	1913	1935	1000
Dropdown	mount	2784	2818	5000
FocusTrapZone	mount	1865	1842	5000
FocusZone	mount	2029	1942	5000
IconButton	mount	1995	1999	5000
Label	mount	361	365	5000
Layer	mount	2224	2201	5000
Link	mount	505	487	5000
MenuButton	mount	1657	1646	5000
MessageBar	mount	2293	2284	5000
Nav	mount	3808	3646	1000
OverflowSet	mount	1524	1589	5000
Panel	mount	1609	1628	1000
Persona	mount	871	886	1000
Pivot	mount	1594	1680	1000
PrimaryButton	mount	1438	1450	5000
Rating	mount	8790	8597	5000
SearchBox	mount	1447	1482	5000
Shimmer	mount	2890	2929	5000
Slider	mount	1610	1639	5000
SpinButton	mount	5754	5688	5000
Spinner	mount	435	456	5000
SplitButton	mount	3543	3542	5000
Stack	mount	559	559	5000
StackWithIntrinsicChildren	mount	1747	1765	5000
StackWithTextChildren	mount	5415	5341	5000
SwatchColorPicker	mount	11276	11439	5000
TagPicker	mount	3030	3098	5000
TeachingBubble	mount	55287	55027	5000
Text	mount	491	488	5000
TextField	mount	1515	1537	5000
Toggle	mount	923	925	5000
button	mount	117	109	5000

[msft-fluent-ui-bot]

🎉office-ui-fabric-react@v7.168.1 has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes
• Official NPM Release
• Test the release with Developer Demo Site